There is a section in Offshore Cruising Ency on drive trains and V-drives. Bottom line, yes they add a layer of complication, are a little less efficient (more drag in the extra direction change) and typically make working on the stuffing box and shaft coupling a nightmare. But sometimes there is no alternative. Personally, having lived with two V-drives (Borg Warner CR71/72 models) I do everything possible to stay away from them. Design wise, we’d rather make the boat 3′ longer so we can fit in a straight drive. However, there are a lot of small boats with V-drives because there just is no other option. Steve